Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How engineers at Digital Equipment Corp. saved Ethernet

spectrum.ieee.org

Post reply on HN
Print view View original

21–30 of 109 posts

Re: How engineers at Digital Equipment Corp. saved Ethernet

#21

Post by Arrath »

freedomben wrote: post #9
jeramey wrote: post #5

Earlier quoted context omitted.

Occasionally people don't understand how to plug extension power cables together, either, especially during times of high stress and low sleep. Once upon a time, when I was in IT support, I got a call from someone in a satellite office across town saying that their computer wouldn't turn on. A new production had begun and everyone was a bit frantic, so this was an urgent request. After asking them to hold the power s…

heh, with power strips that have very long cables, I've seen them plugged into themselves a few times as well.

Like tying a shoelace: the long grey cord goes around the backside of the desk, turns and comes around the front, and back into its own powerstrip.

..Wait why won't it turn on?

Re: How engineers at Digital Equipment Corp. saved Ethernet

#22

Post by gumby »

jeramey wrote: post #19
firecall wrote: post #17

Earlier quoted context omitted.

I was really hoping for some never before known knowledge of how to connect Extension Cables and Power Boards together! But no, turns out someone didnt even manage the basics! LOL There's a reason the IT Crowd have the running joke of 'have you tried turning it off and on again...'! :-)

In all fairness, the person had obviously been awake for over 24 hours and was on their 1,001st cup of coffee. And since earlier in the summer I had crashed the entire ticket scanner network the night before the opening of the weekend festival we had put on by creating a network loop between a couple of non-spanning-tree-speaking network devices, I didn't feel I was in a place to be snarky about it!

> was on their 1,001st cup of coffee

9 cups is a lot but shouldn't cause cognitive disorder.

Re: How engineers at Digital Equipment Corp. saved Ethernet

#23

Post by beachy »

> Mark’s idea didn’t replace Ethernet—and that was its brilliance. By allowing store-and-forward switching between existing CSMA/CD coax-based Ethernets, bridges allowed easy upgrades of existing LANs.

This reminds me of John Carmack's philosophy of great things coming from thinking locally and taking small steps.

> Carmack subscribes to the philosophy that small, incremental steps are the fastest route to meaningful and disruptive innovation. He compares this approach to the "magic of gradient descent" where small steps using local information result in the best outcomes. According to Carmack, this principle is proven by his own experience, and he has observed this in many of the smartest people in the world. He states, "Little tiny steps using local information winds up leading to all the best answers."

Re: How engineers at Digital Equipment Corp. saved Ethernet

#24

Post by non-chalad »

gumby wrote: post #2

What a great story. The spanning tree algo is under appreciated: this allowed people who didn’t understand networking to plug networks together the way you would plug extension power cables together,* making networking simple ( or alternatively insanely broken, when people had 400 computers on a single LAN with a rat’s nest of bridges and hubs…but unlike the extension cord case, nothing would catch literal fire). * d…

Too late: Tried this at work; Did a marvelous job sharing satellite internet with the whole barracks.

Re: How engineers at Digital Equipment Corp. saved Ethernet

#25

Post by KerrAvon »

mixmastamyk wrote: post #15
bluGill wrote: post #12

Earlier quoted context omitted.

Unfortunately none of those people have explained how it could be done in enough detail that I could try it. Most walk away when pressed but a few press on telling me it is easy so shut up and do it .

Similar to how it has been done with phone numbers. I saw this done in Brazil for example. You add a digit to the front and put all existing address on 0.*. Short number dials are assumed to be 0.*. Update OS and hardware. Then you allocate across the new digit much later as time goes on. The thing with phone infrastructure though is that it is centralized. So may happen in a reasonably coordinated rollout. Global in…

The IPv4 address field is fixed size. You can't simply add a digit and deal with it at the telephony company premises like you can with a phone number. You have to rev every piece of equipment and software that can ever touch a packet. At that point, why are you not also fixing other architectural flaws and ensuring that the address space is large enough to accommodate any future needs?

Re: How engineers at Digital Equipment Corp. saved Ethernet

#26

Post by teleforce »

gumby wrote: post #2

What a great story. The spanning tree algo is under appreciated: this allowed people who didn’t understand networking to plug networks together the way you would plug extension power cables together,* making networking simple ( or alternatively insanely broken, when people had 400 computers on a single LAN with a rat’s nest of bridges and hubs…but unlike the extension cord case, nothing would catch literal fire). * d…

That's why the new Ethernet protocol 802.11aq is recommending Shortest Path Bridging (SPB) as a robust alternative to Spanning Tree Protocol (STP). Not only it's more robust, but it is more secure with extra resilience against broadcast storm. It also can support multi-cast function more easily and intuitively at data-link layer [1],[2]. Compared to the new SPB, STP looks like an immature hacks and why it took so long to be replaced is beyond me.

[1]IEEE 802.1aq:

https://en.m.wikipedia.org/wiki/IEEE_802.1aq

[2] 802.1aq Shortest Path Bridging Design and Evolution: The Architect's Perspective:

https://ieeexplore.ieee.org/book/6381532

Re: How engineers at Digital Equipment Corp. saved Ethernet

#27

Post by Alupis »

themerone wrote: post #8
eej71 wrote: post #6

Earlier quoted context omitted.

I think the great architectural challenge would be - how does one add that byte to the IP header in a non-breaking way?

There's a surprising number of people who think you could magically expand the IPv4 address space in a backwards compatible manner.

I believe it's more along the lines of the concepts in IPv4 are easier to grasp than IPv6, starting with the actual addresses themselves.

IPv6 breaks all backwards compatibility. So, it's not unreasonable for people to ask why we can't just break it in a more familiar way?

Extending IPv4 into say, IPv7 and using familiar addressing schemes, well understood routing/NAT/DHCP techniques, etc, while providing the same usable address range as IPv6 is possible.

Re: How engineers at Digital Equipment Corp. saved Ethernet

#28

Post by Alupis »

KerrAvon wrote: post #25
mixmastamyk wrote: post #15

Earlier quoted context omitted.

Similar to how it has been done with phone numbers. I saw this done in Brazil for example. You add a digit to the front and put all existing address on 0.*. Short number dials are assumed to be 0.*. Update OS and hardware. Then you allocate across the new digit much later as time goes on. The thing with phone infrastructure though is that it is centralized. So may happen in a reasonably coordinated rollout. Global in…

The IPv4 address field is fixed size. You can't simply add a digit and deal with it at the telephony company premises like you can with a phone number. You have to rev every piece of equipment and software that can ever touch a packet. At that point, why are you not also fixing other architectural flaws and ensuring that the address space is large enough to accommodate any future needs?

> The IPv4 address field is fixed size.

So?

Make it bigger, call it IPv7, then enjoy.

IPv6 has 128 bits for addresses, why can't IPv7 have 128 bits as well, but still use more familiar patterns/techniques borrowed from IPv4?

IPv6 threw just about everything out the window... for what reason? Two decades of confusion and resistance...

I think at this point in time, people are afraid to say "ya, we overthought the hell out of IPv6".

Re: How engineers at Digital Equipment Corp. saved Ethernet

#29

Post by throw0101d »

teleforce wrote: post #26
gumby wrote: post #2

What a great story. The spanning tree algo is under appreciated: this allowed people who didn’t understand networking to plug networks together the way you would plug extension power cables together,* making networking simple ( or alternatively insanely broken, when people had 400 computers on a single LAN with a rat’s nest of bridges and hubs…but unlike the extension cord case, nothing would catch literal fire). * d…

That's why the new Ethernet protocol 802.11aq is recommending Shortest Path Bridging (SPB) as a robust alternative to Spanning Tree Protocol (STP). Not only it's more robust, but it is more secure with extra resilience against broadcast storm. It also can support multi-cast function more easily and intuitively at data-link layer [1],[2]. Compared to the new SPB, STP looks like an immature hacks and why it took so lon…

> That's why the new Ethernet protocol 802.11aq is recommending Shortest Path Bridging (SPB) as a robust alternative to Spanning Tree Protocol (STP).

This is a dead letter standard: most folks who would 'need' SPB are probably using BGP EVPN to reduce the Layer 2 'blast radius'.

It should also be noted that the IEEE was dragged kicking and screaming towards SPB: originally TRILL was proposed, but the IEEE rejected it, and so the IETF published:

* https://en.wikipedia.org/wiki/TRILL_(computing)

IEEE realized their mistake and published SPB, so now there are two L2 standards.

Not many folks who either though, with anyone really needing 'large scale' stuff moving towards L3 solutions.

Re: How engineers at Digital Equipment Corp. saved Ethernet

#30

Post by ndriscoll »

firecall wrote: post #18
spintin wrote: post #3

[flagged]

Has IPv6 been a failure? All I know is that IPv4 is still around. And without knowing the IP Addresses of devices on my LAN, by home network would be harder to manage!

You can know the IP addresses on your LAN. If you'd like you can assign multiple addresses per interface, so that you have global and local addresses. e.g. local addresses fc00::1 for your router, fc00::2 for your desktop, fc00::3 for your phone, etc. If you want, you can use your global prefix with ::1 ::2 and ::3 for your global addresses too. You don't have to use privacy extensions if you don't want to.

Things like peer to peer calling can actually work though without NAT.

Post reply on HN